The robberies, involving jewellery worth almost RM2 million, happened last November and on Thursday.
Selangor police chief Mazlan Mansor said the suspect aged 25 was among 11 locals detained in separate raids around Petaling Jaya, Shah Alam and Kuala Lumpur on Friday and Saturday.
He said the first robbery in November involved almost RM1.1 million and the second incident on Thursday involved RM750,000.
“Investigations revealed the two cases were an inside job.
“The salesman is also wanted by police to assist in an investigation into a cheating case in Senawang, Negeri Sembilan, under Section 420 of the Penal Code.”
Mazlan said police recovered part of the stolen loot, RM33,420 in cash, a pistol, four live bullets and one spent bullet.
He said the suspects have been remanded until Feb 16 under Section 395/397 of the Penal Code.